automake: use MKDIR_P instead of mkdir -p

modules/gui/macosx/Makefile.am

@@ -30,7 +30,7 @@ xib_verbose_0 = @echo "  XIB     " $@;
 xib_verbose__0 = $(xib_verbose_0)
 
 .xib.nib:
-	$(AM_V_at)mkdir -p -- gui/macosx/UI
+	$(AM_V_at)$(MKDIR_P) "gui/macosx/UI"
 	$(xib_verbose)$(XIB) --errors --warnings --notices \
 	  --module VLC --auto-activate-custom-fonts --target-device mac \
 	  --minimum-deployment-target 10.11 --output-format human-readable-text \

modules/stream_out/Makefile.am

@@ -126,7 +126,7 @@ sout_LTLIBRARIES += $(LTLIBstream_out_chromaprint)
 SUFFIXES += .proto .pb.cc
 
 stream_out/chromecast/@PROTOBUF_VERSION@/cast_channel.pb.cc: stream_out/chromecast/cast_channel.proto
-	$(AM_V_at)mkdir -p stream_out/chromecast/@PROTOBUF_VERSION@
+	$(AM_V_at)$(MKDIR_P) "stream_out/chromecast/@PROTOBUF_VERSION@"
 	$(AM_V_GEN)$(PROTOC) --cpp_out=stream_out/chromecast/@PROTOBUF_VERSION@ -I$(srcdir)/stream_out/chromecast $<
 
 stream_out/chromecast/@PROTOBUF_VERSION@/cast_channel.pb.h: stream_out/chromecast/@PROTOBUF_VERSION@/cast_channel.pb.cc

share/Makefile.am

@@ -149,7 +149,7 @@ skins2_default_vlt_FILES = \
 	skins2/default/subX/vol_slider.png
 
 skins2/default.vlt: $(skins2_default_vlt_FILES)
-	$(AM_V_at)mkdir -p skins2
+	$(AM_V_at)$(MKDIR_P) "skins2"
 	$(AM_V_at)rm -f -- skins2/default.vlt.tmp
 	$(AM_V_GEN)GZIP=--no-name \
 	tar cvvzf skins2/default.vlt.tmp \
@@ -174,7 +174,7 @@ luac_verbose_0 = @echo "  LUAC   $@";
 	done; \
 	echo "Attempt to byte-compile unknown file: $(<)!"; \
 	exit 1
-	$(AM_V_at)mkdir -p "$$(dirname '$@')"
+	$(AM_V_at)$(MKDIR_P) "$$(dirname '$@')"
 	$(luac_verbose)$(LUAC) -o $@ $<
 
 if BUILD_LUA

src/Makefile.am

@@ -148,7 +148,7 @@ noinst_HEADERS = \
 
 ../include/vlc_about.h: Makefile.am $(top_srcdir)/COPYING $(top_srcdir)/THANKS $(top_srcdir)/AUTHORS
 	$(AM_V_at)rm -f -- "$@.tmp"
-	$(AM_V_at)mkdir -p -- ../include
+	$(AM_V_at)$(MKDIR_P) "../include"
 	$(AM_V_GEN)(echo "/* Automatically generated file - DO NOT EDIT */" && \
 	echo "static const char psz_license[] =" && \
 	sed 's/"/\\"/g;s/^.*$$/\"&\\n\"/' "$(top_srcdir)/COPYING" && \