[gimp] Fix clang complaining about missing void in function prototypes.

[John Ralls <jralls src gnome org>]

commit 1d5bffd1c288425214c01025807ecda8e0227c69
Author: John Ralls <jralls ceridwen us>
Date:   Mon Feb 23 15:12:33 2015 -0800

    Fix clang complaining about missing void in function prototypes.

 plug-ins/twain/tw_local.h |    6 +++---
 plug-ins/twain/tw_mac.c   |    5 +++--
 2 files changed, 6 insertions(+), 5 deletions(-)
---
diff --git a/plug-ins/twain/tw_local.h b/plug-ins/twain/tw_local.h
index e76cf87..45b2fca 100644
--- a/plug-ins/twain/tw_local.h
+++ b/plug-ins/twain/tw_local.h
@@ -34,7 +34,7 @@ TW_UINT16 callDSM(pTW_IDENTITY, pTW_IDENTITY,
                  TW_UINT16, TW_MEMREF);
 
 int twainIsAvailable(void);
-void twainQuitApplication ();
+void twainQuitApplication (void);
 gboolean twainSetupCallback (pTW_SESSION twSession);
 
 TW_HANDLE twainAllocHandle(size_t size);
@@ -42,7 +42,7 @@ TW_MEMREF twainLockHandle (TW_HANDLE handle);
 void twainUnlockHandle (TW_HANDLE handle);
 void twainFreeHandle (TW_HANDLE handle);
 
-int twainMain ();
-int scanImage ();
+int twainMain (void);
+int scanImage (void);
 
 #endif
diff --git a/plug-ins/twain/tw_mac.c b/plug-ins/twain/tw_mac.c
index 796d28e..e044e01 100644
--- a/plug-ins/twain/tw_mac.c
+++ b/plug-ins/twain/tw_mac.c
@@ -146,7 +146,7 @@ TW_UINT16 twainCallback(pTW_IDENTITY pOrigin,
   return TWRC_SUCCESS;
 }
 
-void twainQuitApplication ()
+void twainQuitApplication (void)
 {
   QuitApplicationEventLoop();
 }
@@ -192,6 +192,7 @@ static void twainSetupMacUI()
 
   /* Voodoo magic fix inspired by java_swt launcher */
   /* Without this the icon setting doesn't work about half the time. */
+
   CGrafPtr p = BeginQDContextForApplicationDockTile();
   EndQDContextForApplicationDockTile(p);
 
@@ -199,7 +200,7 @@ static void twainSetupMacUI()
 }
 
 int
-twainMain()
+twainMain(void)
 {
   EventLoopTimerRef timer;
   OSStatus err;