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/dri2.c

@@ -303,7 +303,7 @@ DRI2Connect(Display * dpy, XID window, char **driverName, char **deviceName)
       return False;
    }
 
-   *driverName = Xmalloc(rep.driverNameLength + 1);
+   *driverName = malloc(rep.driverNameLength + 1);
    if (*driverName == NULL) {
       _XEatData(dpy,
                 ((rep.driverNameLength + 3) & ~3) +
@@ -315,9 +315,9 @@ DRI2Connect(Display * dpy, XID window, char **driverName, char **deviceName)
    _XReadPad(dpy, *driverName, rep.driverNameLength);
    (*driverName)[rep.driverNameLength] = '\0';
 
-   *deviceName = Xmalloc(rep.deviceNameLength + 1);
+   *deviceName = malloc(rep.deviceNameLength + 1);
    if (*deviceName == NULL) {
-      Xfree(*driverName);
+      free(*driverName);
       _XEatData(dpy, ((rep.deviceNameLength + 3) & ~3));
       UnlockDisplay(dpy);
       SyncHandle();
@@ -431,7 +431,7 @@ DRI2GetBuffers(Display * dpy, XID drawable,
    *height = rep.height;
    *outCount = rep.count;
 
-   buffers = Xmalloc(rep.count * sizeof buffers[0]);
+   buffers = malloc(rep.count * sizeof buffers[0]);
    if (buffers == NULL) {
       _XEatData(dpy, rep.count * sizeof repBuffer);
       UnlockDisplay(dpy);
@@ -490,7 +490,7 @@ DRI2GetBuffersWithFormat(Display * dpy, XID drawable,
    *height = rep.height;
    *outCount = rep.count;
 
-   buffers = Xmalloc(rep.count * sizeof buffers[0]);
+   buffers = malloc(rep.count * sizeof buffers[0]);
    if (buffers == NULL) {
       _XEatData(dpy, rep.count * sizeof repBuffer);
       UnlockDisplay(dpy);