um: Fix CONFIG_GCOV for modules.

Explicitly export symbols so modpost doesn't complain.
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Richard Weinberger <richard@nod.at>

arch/um/kernel/gmon_syms.c

@@ -7,3 +7,10 @@
 
 extern void __bb_init_func(void *)  __attribute__((weak));
 EXPORT_SYMBOL(__bb_init_func);
+
+extern void __gcov_init(void *)  __attribute__((weak));
+EXPORT_SYMBOL(__gcov_init);
+extern void __gcov_merge_add(void *, unsigned int)  __attribute__((weak));
+EXPORT_SYMBOL(__gcov_merge_add);
+extern void __gcov_exit(void)  __attribute__((weak));
+EXPORT_SYMBOL(__gcov_exit);