gendef.h: fix unbalanced #pragma pack(1)

mingw-w64-tools/gendef/src/gendef.h

diff --git a/mingw-w64-tools/gendef/src/gendef.h b/mingw-w64-tools/gendef/src/gendef.h
index 8ee0445..bc04399 100644
--- a/mingw-w64-tools/gendef/src/gendef.h
+++ b/mingw-w64-tools/gendef/src/gendef.h
@@ -375,4 +375,6 @@
 int gendef_getsymbol_info (const char *dllname, const char *symbolname, int *isData, uint32_t *at);
 int gendef_addpath_def (const char *path);
 
+#pragma pack()
+
 #endif