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

This makes Lagom pick up the host math.h, which is what we want.

Libraries/LibM/math.cpp

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