runtime: use "mp" and "gp" instead of "m" and "g" for local variable name to avoid confusion with the global "m" and "g".

R=golang-dev, minux.ma, rsc
CC=bradfitz, golang-dev
https://golang.org/cl/6939064
diff --git a/src/pkg/runtime/runtime.h b/src/pkg/runtime/runtime.h
index e6a78ba..6c9d50e 100644
--- a/src/pkg/runtime/runtime.h
+++ b/src/pkg/runtime/runtime.h
@@ -620,7 +620,7 @@
 void	runtime·ready(G*);
 byte*	runtime·getenv(int8*);
 int32	runtime·atoi(byte*);
-void	runtime·newosproc(M *m, G *g, void *stk, void (*fn)(void));
+void	runtime·newosproc(M *mp, G *gp, void *stk, void (*fn)(void));
 void	runtime·signalstack(byte*, int32);
 G*	runtime·malg(int32);
 void	runtime·asminit(void);