compilation warning "jobserver unavailable" removal

This commit removes the warning:
make[4]: warning: jobserver unavailable: using -j1.  Add '+' to parent make rule.

Basically, inside a Makefile we should use $(MAKE) instead of make.

cmake_targets/CMakeLists.txt

@@ -1880,9 +1880,9 @@ endif (${T_TRACER})
 #This rule and the following deal with it.
 add_custom_command (
   OUTPUT ${OPENAIR_DIR}/common/utils/T/T_IDs.h
-  COMMAND make clean
-  COMMAND make
-  COMMAND make check_vcd
+  COMMAND $(MAKE) clean
+  COMMAND $(MAKE)
+  COMMAND $(MAKE) check_vcd
   WORKING_DIRECTORY ${OPENAIR_DIR}/common/utils/T
   DEPENDS ${OPENAIR_DIR}/common/utils/T/T_messages.txt
           ${OPENAIR_DIR}/common/utils/LOG/vcd_signal_dumper.c
@@ -2235,7 +2235,7 @@ function(make_driver name dir)
   endforeach()
   CONFIGURE_FILE(${OPENAIR_CMAKE}/tools/Kbuild.cmake ${OPENAIR_BIN_DIR}/${name}/Kbuild)
   add_custom_command(OUTPUT ${name}.ko
-    COMMAND make -C ${module_build_path} M=${OPENAIR_BIN_DIR}/${name}
+    COMMAND $(MAKE) -C ${module_build_path} M=${OPENAIR_BIN_DIR}/${name}
     WORKING_DIRECTORY ${OPENAIR_BIN_DIR}/${name}
     COMMENT "building ${module}.ko"
     VERBATIM

common/utils/T/Makefile

@@ -27,4 +27,4 @@ check_vcd:
 
 clean:
 	rm -f *.o $(GENIDS) core T_IDs.h T_messages.txt.h _check_vcd
-	cd tracer && make clean
+	cd tracer && $(MAKE) clean

common/utils/T/tracer/Makefile

@@ -63,16 +63,16 @@ multi: multi.o utils.o database.o config.o
 .PHONY: all gui/gui.a view/view.a logger/logger.a filter/filter.a
 
 gui/gui.a:
-	cd gui && make
+	cd gui && $(MAKE)
 
 view/view.a:
-	cd view && make
+	cd view && $(MAKE)
 
 logger/logger.a:
-	cd logger && make
+	cd logger && $(MAKE)
 
 filter/filter.a:
-	cd filter && make
+	cd filter && $(MAKE)
 
 %.o: %.c
 	$(CC) $(CFLAGS) -c -o $@ $<
@@ -81,8 +81,8 @@ clean:
 	rm -f *.o core tracer_remote textlog enb ue vcd record replay
 	rm -f extract_config macpdu2wireshark extract_input_subframe
 	rm -f extract_output_subframe to_vcd extract multi
-	cd gui && make clean
-	cd view && make clean
-	cd logger && make clean
-	cd filter && make clean
-	cd hacks && make clean
+	cd gui && $(MAKE) clean
+	cd view && $(MAKE) clean
+	cd logger && $(MAKE) clean
+	cd filter && $(MAKE) clean
+	cd hacks && $(MAKE) clean