core: mem/f_malloc - explicit set to 0 for bit shifting greater than …

…size

(cherry picked from commit 0cb33ab)

src/core/mem/f_malloc.c

@@ -122,7 +122,8 @@ inline static int fm_bmp_first_set(struct fm_block* qm, int start)
 				return (start-bit+r);
 		}
 #endif
-		v=qm->free_bitmap[bmp_idx]>>(bit+1);
+		if((bit+1) < 8*sizeof(v)) v=qm->free_bitmap[bmp_idx]>>(bit+1);
+		else v = 0;
 		return start+1+bit_scan_forward((unsigned long)v);
 	}
 	for (r=bmp_idx+1;r<FM_HASH_BMP_SIZE; r++){