fix for -fno-common

main.c:317: warning: dereferencing 'void *' pointer
main.c:317: error: request for member '_file' in something not a structure or union

Index: src/main.c
--- src/main.c.orig
+++ src/main.c
@@ -47,6 +47,7 @@
 #include <dmalloc.h>
 #endif /* HAVE_LIBDMALLOC */
 
+option_t config;
 regex_t posix_pattern;
 #ifdef HAVE_LIBPCRE
 pcre *pcre_pattern;
@@ -55,7 +56,7 @@ pcre_extra *hints;
 char *boxname, *outboxname, *pipecmd, *tmpfilename;
 int maildir_count = 0;
 int count = 0;
-void *tmpp;
+FILE *tmpp;
 checksum_t *cs;
 
 int