stand: Minor cleanup

Replace a cast '0' for a null pointers with NULL
Replace a 'goto loop' with a do-while loop in ufs and ext2fs.
Cast cp pointer to uintptr_t to test to see if it's aligned rather than long.

[ minor tweaks based on my & hps' review, reworded commit message ]
Reviewed by: imp, hps
Pull Request: https://github.com/freebsd/freebsd-src/pull/547

3 files changed, 27 insertions, 24 deletions

diff --git a/stand/libsa/ext2fs.c b/stand/libsa/ext2fs.c
index 3e91d9fd516f..043da159f0ee 100644
--- a/stand/libsa/ext2fs.c
+++ b/stand/libsa/ext2fs.c
@@ -796,10 +796,11 @@ ext2fs_close(struct open_file *f)
 	struct file *fp = (struct file *)f->f_fsdata;
 	int level;
 
-	f->f_fsdata = (void *)0;
-	if (fp == (struct file *)0)
+	if (fp == NULL)
 		return (0);
 
+	f->f_fsdata = NULL;
+
 	for (level = 0; level < EXT2_NIADDR; level++) {
 		if (fp->f_blk[level])
 			free(fp->f_blk[level]);
@@ -891,16 +892,17 @@ ext2fs_readdir(struct open_file *f, struct dirent *d)
 	/*
 	 * assume that a directory entry will not be split across blocks
 	 */
-again:
-	if (fp->f_seekp >= fp->f_di.di_size)
-		return (ENOENT);
-	error = buf_read_file(f, &buf, &buf_size);
-	if (error)
-		return (error);
-	ed = (struct ext2dirent *)buf;
-	fp->f_seekp += ed->d_reclen;
-	if (ed->d_ino == (ino_t)0)
-		goto again;
+
+	do {
+		if (fp->f_seekp >= fp->f_di.di_size)
+			return (ENOENT);
+		error = buf_read_file(f, &buf, &buf_size);
+		if (error)
+			return (error);
+		ed = (struct ext2dirent *)buf;
+		fp->f_seekp += ed->d_reclen;
+	} while (ed->d_ino == (ino_t)0);
+
 	d->d_type = EXTFTODT(ed->d_type);
 	strncpy(d->d_name, ed->d_name, ed->d_namlen);
 	d->d_name[ed->d_namlen] = '\0';
diff --git a/stand/libsa/in_cksum.c b/stand/libsa/in_cksum.c
index 2f8c448fc0eb..590a304271d0 100644
--- a/stand/libsa/in_cksum.c
+++ b/stand/libsa/in_cksum.c
@@ -61,7 +61,7 @@ in_cksum(void *p, int len)
 			sum += v + *cp++;
 			len--;
 		}
-		if (((long)cp & 1) == 0) {
+		if (((uintptr_t)cp & 1) == 0) {
 			while ((len -= 2) >= 0) {
 				sum += *(u_short *)cp;
 				cp += 2;
diff --git a/stand/libsa/ufs.c b/stand/libsa/ufs.c
index 769fe9120ee6..cb4c7ca6453c 100644
--- a/stand/libsa/ufs.c
+++ b/stand/libsa/ufs.c
@@ -409,7 +409,7 @@ buf_read_file(struct open_file *f, char **buf_p, size_t *size_p)
 	block_size = sblksize(fs, DIP(fp, di_size), file_block);
 
 	if (file_block != fp->f_buf_blkno) {
-		if (fp->f_buf == (char *)0)
+		if (fp->f_buf == NULL)
 			fp->f_buf = malloc(fs->fs_bsize);
 
 		rc = block_map(f, file_block, &disk_block);
@@ -888,16 +888,17 @@ ufs_readdir(struct open_file *f, struct dirent *d)
 	/*
 	 * assume that a directory entry will not be split across blocks
 	 */
-again:
-	if (fp->f_seekp >= DIP(fp, di_size))
-		return (ENOENT);
-	error = buf_read_file(f, &buf, &buf_size);
-	if (error)
-		return (error);
-	dp = (struct direct *)buf;
-	fp->f_seekp += dp->d_reclen;
-	if (dp->d_ino == (ino_t)0)
-		goto again;
+
+	do {
+		if (fp->f_seekp >= DIP(fp, di_size))
+			return (ENOENT);
+		error = buf_read_file(f, &buf, &buf_size);
+		if (error)
+			return (error);
+		dp = (struct direct *)buf;
+		fp->f_seekp += dp->d_reclen;
+	} while (dp->d_ino == (ino_t)0);
+
 	d->d_type = dp->d_type;
 	strcpy(d->d_name, dp->d_name);
 	return (0);