[MIPS] Use "=R" constraint to avoid compiler errors in cmpxchg().
    
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/include/asm-mips/system.h b/include/asm-mips/system.h
index e8e5d41..ddae9ba 100644
--- a/include/asm-mips/system.h
+++ b/include/asm-mips/system.h
@@ -322,7 +322,7 @@
 #endif
 		"2:							\n"
 		"	.set	pop					\n"
-		: "=&r" (retval), "=m" (*m)
+		: "=&r" (retval), "=R" (*m)
 		: "R" (*m), "Jr" (old), "Jr" (new)
 		: "memory");
 	} else if (cpu_has_llsc) {
@@ -342,7 +342,7 @@
 #endif
 		"2:							\n"
 		"	.set	pop					\n"
-		: "=&r" (retval), "=m" (*m)
+		: "=&r" (retval), "=R" (*m)
 		: "R" (*m), "Jr" (old), "Jr" (new)
 		: "memory");
 	} else {
@@ -379,7 +379,7 @@
 #endif
 		"2:							\n"
 		"	.set	pop					\n"
-		: "=&r" (retval), "=m" (*m)
+		: "=&r" (retval), "=R" (*m)
 		: "R" (*m), "Jr" (old), "Jr" (new)
 		: "memory");
 	} else if (cpu_has_llsc) {
@@ -397,7 +397,7 @@
 #endif
 		"2:							\n"
 		"	.set	pop					\n"
-		: "=&r" (retval), "=m" (*m)
+		: "=&r" (retval), "=R" (*m)
 		: "R" (*m), "Jr" (old), "Jr" (new)
 		: "memory");
 	} else {