ptrace: cleanup arch_ptrace() on microblaze

Remove checking @addr greater than 0 because @addr is now unsigned.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Michal Simek <monstr@monstr.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/microblaze/kernel/ptrace.c

@@ -100,7 +100,7 @@ long arch_ptrace(struct task_struct *child, long request,
 			} else {
 				rval = -EIO;
 			}
-		} else if (addr >= 0 && addr < PT_SIZE && (addr & 0x3) == 0) {
+		} else if (addr < PT_SIZE && (addr & 0x3) == 0) {
 			microblaze_reg_t *reg_addr = reg_save_addr(addr, child);
 			if (request == PTRACE_PEEKUSR)
 				val = *reg_addr;