Revert "LibM: Always include <math.h> instead of <LibM/math.h>"

This reverts commit dc12cbca41.

Sadly this broke the build due to some confusion about <new>.
Reverting until this can be solved fully.

Libraries/LibM/math.cpp

@@ -25,7 +25,7 @@
  */
 
 #include <LibC/assert.h>
-#include <math.h>
+#include <LibM/math.h>
 #include <stdint.h>
 #include <stdlib.h>