powerpc/xmon: Make xmon_getchar() static

xmon_getchar() is only called from within nonstdio.c, so make it static.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/xmon/nonstdio.c b/arch/powerpc/xmon/nonstdio.c
index a225d80..2209485 100644
--- a/arch/powerpc/xmon/nonstdio.c
+++ b/arch/powerpc/xmon/nonstdio.c
@@ -23,7 +23,7 @@
 static char *lineptr;
 static int lineleft;
 
-int xmon_getchar(void)
+static int xmon_getchar(void)
 {
 	int c;