JFS: Get rid of "may be used uninitialized" warnings

Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
diff --git a/fs/jfs/jfs_txnmgr.c b/fs/jfs/jfs_txnmgr.c
index 6988a10..03893ac 100644
--- a/fs/jfs/jfs_txnmgr.c
+++ b/fs/jfs/jfs_txnmgr.c
@@ -1919,7 +1919,8 @@
 	 * header ?
 	 */
 	if (tlck->type & tlckTRUNCATE) {
-		pxd_t pxd;	/* truncated extent of xad */
+		/* This odd declaration suppresses a bogus gcc warning */
+		pxd_t pxd = pxd;	/* truncated extent of xad */
 		int twm;
 
 		/*