Remove Xcalloc/Xmalloc/Xfree calls

These calls allowed Xlib to use a custom memory allocator, but Xlib has
used the standard C library functions since at least its initial import
into git in 2003. It seems unlikely that it will grow a custom memory
allocator. The functions now just add extra overhead. Replacing them
will make future Coccinelle patches simpler.

This patch has been generated by the following Coccinelle semantic
patch:

// Remove Xcalloc/Xmalloc/Xfree calls

@@ expression E1, E2; @@
- Xcalloc (E1, E2)
+ calloc (E1, E2)

@@ expression E; @@
- Xmalloc (E)
+ malloc (E)

@@ expression E; @@
- Xfree (E)
+ free (E)

@@ expression E; @@
- XFree (E)
+ free (E)

Reviewed-by: Brian Paul <brianp@vmware.com>

src/glx/renderpix.c

@@ -84,7 +84,7 @@ __glXSendLargeImage(struct glx_context * gc, GLint compsize, GLint dim,
                     GLubyte * pc, GLubyte * modes)
 {
     /* Allocate a temporary holding buffer */
-    GLubyte *buf = (GLubyte *) Xmalloc(compsize);
+    GLubyte *buf = (GLubyte *) malloc(compsize);
     if (!buf) {
 	__glXSetError(gc, GL_OUT_OF_MEMORY);
 	return;
@@ -108,7 +108,7 @@ __glXSendLargeImage(struct glx_context * gc, GLint compsize, GLint dim,
     __glXSendLargeCommand(gc, gc->pc, pc - gc->pc, buf, compsize);
 
     /* Free buffer */
-    Xfree((char *) buf);
+    free((char *) buf);
 }
 
 /************************************************************************/
@@ -178,7 +178,7 @@ __indirect_glSeparableFilter2D(GLenum target, GLenum internalformat,
       pc += hdrlen;
 
       /* Allocate a temporary holding buffer */
-      buf = (GLubyte *) Xmalloc(bufsize);
+      buf = (GLubyte *) malloc(bufsize);
       if (!buf) {
          __glXSetError(gc, GL_OUT_OF_MEMORY);
          return;
@@ -193,6 +193,6 @@ __indirect_glSeparableFilter2D(GLenum target, GLenum internalformat,
       __glXSendLargeCommand(gc, gc->pc, (GLint) (pc - gc->pc), buf,
                             bufsize);
       /* Free buffer */
-      Xfree((char *) buf);
+      free((char *) buf);
    }
 }