Qt c++ function name shadow warnings

We have a struct called mkroom and a function called mkroom()
so c++ complains about the mkroom() function hiding the
initializer for the struct.

Similarly, we have a struct called attack and a function
called attack().

There may be a more elegant way of eliminating those two
warnings, but renaming mkroom() to do_mkroom() and
attack() to do_attack() was straightforward enough.

src/mhitm.c

@@ -197,7 +197,7 @@ mdisplacem(register struct monst *magr, register struct monst *mdef,
     if (m_at(fx, fy) != magr || m_at(tx, ty) != mdef)
         return MM_MISS;
 
-    /* The 1 in 7 failure below matches the chance in attack()
+    /* The 1 in 7 failure below matches the chance in do_attack()
      * for pet displacement.
      */
     if (!rn2(7))