rtla: Don't overwrite existing directory mode

The mode on /usr/bin is often 555 these days,
but make install on rtla overwrites this with 755

Fix this by preserving the current directory if it exists.

Link: https://lkml.kernel.org/r/8c294a6961080a1970fd8b73f7bcf1e3984579e2.1651247710.git.bristot@kernel.org
Link: https://lore.kernel.org/r/20220402043939.6962-1-jkacur@redhat.com

Cc: Daniel Bristot de Oliveria <bristot@redhat.com>
Fixes: 79ce8f4 ("rtla: Real-Time Linux Analysis tool")
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: John Kacur <jkacur@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Author: John Kacur

tools/tracing/rtla/Makefile

@@ -23,6 +23,7 @@ $(call allow-override,LD_SO_CONF_PATH,/etc/ld.so.conf.d/)
 $(call allow-override,LDCONFIG,ldconfig)
 
 INSTALL	=	install
+MKDIR	=	mkdir
 FOPTS	:=	-flto=auto -ffat-lto-objects -fexceptions -fstack-protector-strong \
 		-fasynchronous-unwind-tables -fstack-clash-protection
 WOPTS	:= 	-Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -Wno-maybe-uninitialized
@@ -103,7 +104,7 @@ static: $(OBJ)
 
 .PHONY: install
 install: doc_install
-	$(INSTALL) -d -m 755 $(DESTDIR)$(BINDIR)
+	$(MKDIR) -p $(DESTDIR)$(BINDIR)
 	$(INSTALL) rtla -m 755 $(DESTDIR)$(BINDIR)
 	$(STRIP) $(DESTDIR)$(BINDIR)/rtla
 	@test ! -f $(DESTDIR)$(BINDIR)/osnoise || rm $(DESTDIR)$(BINDIR)/osnoise