Correct definition of extern variables

Keygender32/BGM.c

@@ -5,6 +5,8 @@
 #include <xmp.h>
 #include "Debug.h"
 
+char *MusicStartFailReason;
+
 static DWORD WINAPI MusicThreadProc(LPVOID);
 
 struct _BgmState {

Keygender32/BGM.h

@@ -17,4 +17,4 @@ void EndMusic(BgmState);
 // current state on success: 0 is playing, 1 is paused.
 int TogglePlayPause(BgmState state);
 
-char *MusicStartFailReason;
+extern char *MusicStartFailReason;

Keygender32/Starfield.c

@@ -5,6 +5,7 @@
 #include <math.h>
 #include <time.h>
 
+UINT WMU_FRAMERATE;
 #define WMU_FRAMERATE_NAME _T("SetFramerate_{6CFC2304-CE89-40c4-881C-988D36FBB978}")
 #define DENSITY 3
 #define LAYERS 5

Keygender32/Starfield.h

@@ -11,4 +11,4 @@ void DeinitStarfieldControl(HINSTANCE);
 
 // Defined by InitStarFieldControl. Send this message to define the
 // rough framerate the control tries to render at.
-UINT WMU_FRAMERATE;
+extern UINT WMU_FRAMERATE;