Clean up error reporting in block.c, so that it gives honest error strings

for the sorts of errors we run into[1].  This also gives us room to put in a
vaguely appropriate casts to silence warnings since our compiler doesn't like
when we compare ssize_t to size_t[2].  Add a cast in sblock.c[3] to silence
a warning because of signed vs. size_t hell (again).  Clean up nearby
excessive parenthemutilation[4].

Reviewed by:	bde [2] [3]
Suggested by:	bde, many [1]
Submitted by:	bde [4]

An aside about [4], bde notes that we do not check for a negative value for
the fs bsize.  I'm nto going to do that in every situation we use it, one must
expect a reasonable program to pass down reasonable values.  Some foot shooting
protection I will tolerate, some I will not.  Also he suggests some possible
conditional improvements there, which I may take to heart.

PS: For me at least, this is now WARNS=5 clean...

1 files changed, 4 insertions, 4 deletions

diff --git a/lib/libufs/sblock.c b/lib/libufs/sblock.c
index 455fee0..7f87f65 100644
--- a/lib/libufs/sblock.c
+++ b/lib/libufs/sblock.c
@@ -64,11 +64,11 @@ sbread(struct uufsd *disk)
 		}
 		if (fs->fs_magic == FS_UFS1_MAGIC)
 			disk->d_ufs = 1;
-		if ((fs->fs_magic == FS_UFS2_MAGIC) &&
-		    (fs->fs_sblockloc == superblock))
+		if (fs->fs_magic == FS_UFS2_MAGIC &&
+		    fs->fs_sblockloc == superblock)
 			disk->d_ufs = 2;
-		if ((fs->fs_bsize <= MAXBSIZE) &&
-		    (fs->fs_bsize >= sizeof(*fs))) {
+		if (fs->fs_bsize <= MAXBSIZE &&
+		    (size_t)fs->fs_bsize >= sizeof(*fs)) {
 			if (disk->d_ufs)
 				break;
 		}