wrlib: Use a Conditional for XPM in the makefile instead of #if in source

Now that the builtin XPM loading is separated from the saving code, the
use of the conditionals provided by autotools provides a better result
as it avoids unnecessary compilation.

Signed-off-by: Christophe CURIS <christophe.curis@free.fr>

wrlib/Makefile.am

@@ -34,7 +34,6 @@ libwraster_la_SOURCES = 	\
 	scale.c		\
 	rotate.c	\
 	convolve.c	\
-	nxpm.c		\
 	save_xpm.c	\
 	xutil.c		\
 	ppm.c
@@ -57,6 +56,8 @@ endif
 
 if USE_XPM
 libwraster_la_SOURCES += xpm.c
+else
+libwraster_la_SOURCES += nxpm.c
 endif
 
 LTCOMPILE2=`echo $(LTCOMPILE) | sed -e s/-fomit-frame-pointer//`

wrlib/nxpm.c

@@ -52,7 +52,6 @@
 
 #define LINEWIDTH 64
 
-#ifndef USE_XPM
 
 static void free_color_symbol_table(unsigned char *color_table[],
 				     unsigned short *symbol_table)
@@ -444,5 +443,3 @@ RImage *RLoadXPM(RContext * context, const char *file)
 		RReleaseImage(image);
 	return NULL;
 }
-
-#endif