Rename kfree to kmm_free for consistency with other naming conventions

graphics/nxbe/nxbe_clipper.c

@@ -262,7 +262,7 @@ void nxbe_clipper(FAR struct nxbe_window_s *wnd,
 
   if (stack.stack)
     {
-      kfree(stack.stack);
+      kmm_free(stack.stack);
     }
 }
 

graphics/nxbe/nxbe_colormap.c

@@ -152,7 +152,7 @@ int nxbe_colormap(FAR NX_DRIVERTYPE *dev)
 
   ret = dev->putcmap(dev, &cmap);
 
-  kfree(alloc);
+  kmm_free(alloc);
   return ret;
 }
 #endif

graphics/nxconsole/nxcon_font.c

@@ -102,7 +102,7 @@ static void nxcon_freeglyph(FAR struct nxcon_glyph_s *glyph)
 {
   if (glyph->bitmap)
     {
-      kfree(glyph->bitmap);
+      kmm_free(glyph->bitmap);
     }
   memset(glyph, 0, sizeof(struct nxcon_glyph_s));
 }

graphics/nxconsole/nxcon_register.c

@@ -155,6 +155,6 @@ FAR struct nxcon_state_s *
   return (NXCONSOLE)priv;
 
 errout:
-  kfree(priv);
+  kmm_free(priv);
   return NULL;
 }

graphics/nxconsole/nxcon_unregister.c

@@ -108,7 +108,7 @@ void nxcon_unregister(NXCONSOLE handle)
       FAR struct nxcon_glyph_s *glyph = &priv->glyph[i];
       if (glyph->bitmap)
         {
-          kfree(glyph->bitmap);
+          kmm_free(glyph->bitmap);
         }
     }
 
@@ -119,5 +119,5 @@ void nxcon_unregister(NXCONSOLE handle)
 
   /* Free the private data structure */
 
-  kfree(handle);
+  kmm_free(handle);
 }

graphics/nxmu/nxmu_kbdin.c

@@ -111,7 +111,7 @@ void nxmu_kbdin(FAR struct nxfe_state_s *fe, uint8_t nch, FAR uint8_t *ch)
         }
 
       (void)nxmu_sendclientwindow(fe->be.topwnd, outmsg, size);
-      kfree(outmsg);
+      kmm_free(outmsg);
     }
 }