xfs: tidy up xfs_rtallocate_extent_exact

Use common code for both xfs_rtallocate_range calls by moving
the !isfree logic into the non-default branch.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>

fs/xfs/xfs_rtalloc.c

@@ -350,17 +350,7 @@ xfs_rtallocate_extent_exact(
 	if (error)
 		return error;
 
-	if (isfree) {
-		/*
-		 * If it is, allocate it and return success.
-		 */
-		error = xfs_rtallocate_range(args, start, maxlen);
-		if (error)
-			return error;
-		*len = maxlen;
-		*rtx = start;
-		return 0;
-	}
+	if (!isfree) {
 		/*
 		 * If not, allocate what there is, if it's at least minlen.
 		 */
@@ -376,6 +366,8 @@ xfs_rtallocate_extent_exact(
 			if (maxlen < minlen)
 				return -ENOSPC;
 		}
+	}
+
 	/*
 	 * Allocate what we can and return it.
 	 */