dri/r200: rename __atom to current_atom.

__atom is defined by gcc when the atom compile optimizations are used.

src/mesa/drivers/dri/r200/r200_cmdbuf.c

@@ -47,9 +47,9 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 #define insert_at_tail_if(atom_list, atom) \
    do { \
-      struct radeon_state_atom* __atom = (atom); \
-      if (__atom->check) \
-	 insert_at_tail((atom_list), __atom); \
+      struct radeon_state_atom* current_atom = (atom); \
+      if (current__atom->check) \
+	 insert_at_tail((atom_list), current_atom); \
    } while(0)
 
 void r200SetUpAtomList( r200ContextPtr rmesa )