xfs: Fix 'set but not used' warning in xfs_bmap_compute_alignments()

With both CONFIG_XFS_DEBUG and CONFIG_XFS_WARN disabled, the only reference to
local variable "error" in xfs_bmap_compute_alignments() gets eliminated during
pre-processing stage of the compilation process. This causes the compiler to
generate a "set but not used" warning.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Brian Foster <bfoster@redhat.com>

fs/xfs/libxfs/xfs_bmap.c

@@ -3471,7 +3471,6 @@ xfs_bmap_compute_alignments(
 	struct xfs_mount	*mp = args->mp;
 	xfs_extlen_t		align = 0; /* minimum allocation alignment */
 	int			stripe_align = 0;
-	int			error;
 
 	/* stripe alignment for allocation is determined by mount parameters */
 	if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC))
@@ -3484,10 +3483,10 @@ xfs_bmap_compute_alignments(
 	else if (ap->datatype & XFS_ALLOC_USERDATA)
 		align = xfs_get_extsz_hint(ap->ip);
 	if (align) {
-		error = xfs_bmap_extsize_align(mp, &ap->got, &ap->prev,
-						align, 0, ap->eof, 0, ap->conv,
-						&ap->offset, &ap->length);
-		ASSERT(!error);
+		if (xfs_bmap_extsize_align(mp, &ap->got, &ap->prev, align, 0,
+					ap->eof, 0, ap->conv, &ap->offset,
+					&ap->length))
+			ASSERT(0);
 		ASSERT(ap->length);
 	}