memtest86+: Fix build warnings

With increased error checking, the memset() call complains about dropping
the volatile and there are multiple outsb() functions defined.

Change-Id: Id626e533737d5aa4b5227ab341177efb15473499
Signed-off-by: Ben Gardner <gardner.ben@gmail.com>
Reviewed-on: https://review.coreboot.org/13909
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/io.h b/io.h
index b3779e4..a38f92e 100644
--- a/io.h
+++ b/io.h
@@ -55,7 +55,7 @@
 __IN1(s##c_p) __IN2(s,s1,"") : "=a" (_v) : "id" (port) ,##i ); SLOW_DOWN_IO; return _v; }
 
 #define __OUTS(s) \
-extern inline void outs##s(unsigned short port, const void * addr, unsigned long count) \
+static inline void outs##s(unsigned short port, const void * addr, unsigned long count) \
 { __asm__ __volatile__ ("cld ; rep ; outs" #s \
 : "=S" (addr), "=c" (count) : "d" (port),"0" (addr),"1" (count)); }