Group clean-app commands

Smaller non-verbose output.

core/erlc.mk

@@ -93,5 +93,5 @@ erlc-include:
 	fi
 
 clean-app:
-	$(gen_verbose) rm -rf ebin/ priv/mibs/
-	$(gen_verbose) rm -f $(addprefix include/,$(addsuffix .hrl,$(notdir $(basename $(wildcard mibs/*.mib)))))
+	$(gen_verbose) rm -rf ebin/ priv/mibs/ \
+		$(addprefix include/,$(addsuffix .hrl,$(notdir $(basename $(wildcard mibs/*.mib)))))

erlang.mk

@@ -294,8 +294,8 @@ erlc-include:
 	fi
 
 clean-app:
-	$(gen_verbose) rm -rf ebin/ priv/mibs/
-	$(gen_verbose) rm -f $(addprefix include/,$(addsuffix .hrl,$(notdir $(basename $(wildcard mibs/*.mib)))))
+	$(gen_verbose) rm -rf ebin/ priv/mibs/ \
+		$(addprefix include/,$(addsuffix .hrl,$(notdir $(basename $(wildcard mibs/*.mib)))))
 
 # Copyright (c) 2014, Loïc Hoguin <essen@ninenines.eu>
 # This file is part of erlang.mk and subject to the terms of the ISC License.