Give make information when used without arguments

Signed-off-by: falkTX <falktx@falktx.com>

Makefile

@@ -5,15 +5,15 @@
 #
 
 all:
-# $(info usage: ${0} 32|64)
+	@echo "error: you must pass '32' or '64' as an argument to this Makefile in order to build WineASIO"
 
 # ---------------------------------------------------------------------------------------------------------------------
 
 32:
-	$(MAKE) ARCH=i386 M=32
+	$(MAKE) build ARCH=i386 M=32
 
 64:
-	$(MAKE) ARCH=x86_64 M=64
+	$(MAKE) build ARCH=x86_64 M=64
 
 # ---------------------------------------------------------------------------------------------------------------------
 

Makefile.mk

@@ -83,7 +83,8 @@ C_SRCS                = $(wineasio_dll_C_SRCS)
 
 ### Generic targets
 
-all: rtaudio/include/asio.h $(DLLS:%=build$(M)/%.so)
+all:
+build: rtaudio/include/asio.h $(DLLS:%=build$(M)/%.so)
 
 ### Build rules