GCC4.6: Squash warning in cmd_mem.c

cmd_mem.c: In function ‘do_mem_loop’:
cmd_mem.c:474:25: warning: variable ‘junk’ set but not used
[-Wunused-but-set-variable]

The assigned variable can be removed because the pointers are volatile so
accesses to their addresses are always generated.

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
diff --git a/common/cmd_mem.c b/common/cmd_mem.c
index 4daa1b3..e84cc4e 100644
--- a/common/cmd_mem.c
+++ b/common/cmd_mem.c
@@ -471,7 +471,7 @@
 
 int do_mem_loop (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
-	ulong	addr, length, i, junk;
+	ulong	addr, length, i;
 	int	size;
 	volatile uint	*longp;
 	volatile ushort *shortp;
@@ -518,7 +518,7 @@
 			longp = (uint *)addr;
 			i = length;
 			while (i-- > 0)
-				junk = *longp++;
+				*longp++;
 		}
 	}
 	if (size == 2) {
@@ -526,14 +526,14 @@
 			shortp = (ushort *)addr;
 			i = length;
 			while (i-- > 0)
-				junk = *shortp++;
+				*shortp++;
 		}
 	}
 	for (;;) {
 		cp = (u_char *)addr;
 		i = length;
 		while (i-- > 0)
-			junk = *cp++;
+			*cp++;
 	}
 }