libc.obj: export missed vfprintf (#634)

The `vfprintf` function is declared in the header files, but is not exported in the library.

Reviewed-on: #634
Co-authored-by: Egor00f <y.yarin@inbox.ru>

programs/develop/ktcc/bin/lib/libc.def

@@ -13,6 +13,7 @@ fgetpos
 fgets
 fopen
 fprintf
+vfprintf
 fputc
 fputs
 fread

programs/develop/ktcc/libc.obj/source/libc.c

@@ -204,6 +204,7 @@ ksys_dll_t EXPORTS[] = {
     { "tmpfile", &tmpfile },
     { "tmpnam", &tmpnam },
     { "vfscanf", &vfscanf },
+    { "vfprintf", &vfprintf },
     { "vprintf", &vprintf },
     { "vfscanf", &vfscanf },
     { "vsprintf", &vsprintf },