Fix strchr for basic non-sse case on x86

Fix source location. Move declaration of __strchr_chk out of
ifdef __BIONIC_FORTIFY which should be available for strchr.cpp
compilation when __BIONIC_FORTIFY is not defined.

Change-Id: I552a6e16656e59b276b322886cfbf57bbfb2e6a7
Signed-off-by: Pavel Chupin <pavel.v.chupin@intel.com>
diff --git a/libc/arch-x86/x86.mk b/libc/arch-x86/x86.mk
index 19c1402..ada5d69 100644
--- a/libc/arch-x86/x86.mk
+++ b/libc/arch-x86/x86.mk
@@ -72,7 +72,7 @@
 	arch-x86/string/bzero.S \
 	bionic/memrchr.c \
 	bionic/memchr.c \
-	string/strchr.cpp \
+	bionic/strchr.cpp \
 	string/strrchr.c \
 	string/index.c \
 	bionic/strnlen.c \
diff --git a/libc/include/string.h b/libc/include/string.h
index f6b4acf..10ff722 100644
--- a/libc/include/string.h
+++ b/libc/include/string.h
@@ -46,6 +46,8 @@
 
 extern char*  index(const char *, int) __purefunc;
 extern char*  strchr(const char *, int) __purefunc;
+extern char* __strchr_chk(const char *, int, size_t);
+
 extern char*  strrchr(const char *, int) __purefunc;
 
 extern size_t strlen(const char *) __purefunc;
@@ -238,8 +240,6 @@
     return __strlen_chk(s, bos);
 }
 
-extern char* __strchr_chk(const char *, int, size_t);
-
 __BIONIC_FORTIFY_INLINE
 char* strchr(const char *s, int c) {
     size_t bos = __bos(s);