build: Normalize HAVE_SUID

See commit 15d7938 ("Try to fix #2310 -- Can't create run directory
without suid-root", 2021-05-13) / PR #4273.

It is the only "HAVE_" option whose value is set by if/else on a
makefile.  Also, it is set in different places to either "yes", "no",
blank or "-DHAVE_SUID".  Set the value only on configure.ac and only to
either blank or to "-DHAVE_SUID".

Misc: The `ifeq ($(HAVE_SUID),-DHAVE_SUID)` comparison that this adds is
based on the existing `ifeq ($(HAVE_APPARMOR),-DHAVE_APPARMOR)`
comparison on Makefile.in.

Makefile.in

@@ -105,7 +105,7 @@ realinstall:
  # firejail executable
  install -m 0755 -d $(DESTDIR)$(bindir)
  install -m 0755 src/firejail/firejail $(DESTDIR)$(bindir)
-ifeq ($(HAVE_SUID),yes)
+ifeq ($(HAVE_SUID),-DHAVE_SUID)
  chmod u+s $(DESTDIR)$(bindir)/firejail
 endif
  # firemon executable

configure

@@ -3757,10 +3757,9 @@ if test "${enable_suid+set}" = set; then :
  enableval=$enable_suid;
 fi
 
-if test "x$enable_suid" = "xno"; then :
- HAVE_SUID="no"
-else
- HAVE_SUID="yes"
+if test "x$enable_suid" != "xno"; then :
+
+ HAVE_SUID="-DHAVE_SUID"
 
 fi
 
@@ -3854,7 +3853,7 @@ if test "x$enable_lts" = "xyes"; then :
  HAVE_USERNS=""
  HAVE_X11=""
  HAVE_FILE_TRANSFER=""
- HAVE_SUID="yes"
+ HAVE_SUID="-DHAVE_SUID"
  BUSYBOX_WORKAROUND="no"
  HAVE_CONTRIB_INSTALL="no",
 

configure.ac

@@ -191,10 +191,9 @@ HAVE_SUID=""
 AC_SUBST([HAVE_SUID])
 AC_ARG_ENABLE([suid],
  [AS_HELP_STRING([--disable-suid], [install as a non-SUID executable])])
-AS_IF([test "x$enable_suid" = "xno"],
- [HAVE_SUID="no"],
- [HAVE_SUID="yes"]
-)
+AS_IF([test "x$enable_suid" != "xno"], [
+ HAVE_SUID="-DHAVE_SUID"
+])
 
 HAVE_FATAL_WARNINGS=""
 AC_SUBST([HAVE_FATAL_WARNINGS])
@@ -257,7 +256,7 @@ AS_IF([test "x$enable_lts" = "xyes"], [
  HAVE_USERNS=""
  HAVE_X11=""
  HAVE_FILE_TRANSFER=""
- HAVE_SUID="yes"
+ HAVE_SUID="-DHAVE_SUID"
  BUSYBOX_WORKAROUND="no"
  HAVE_CONTRIB_INSTALL="no",
 ])

src/common.mk.in

@@ -22,11 +22,7 @@ HAVE_FIRETUNNEL=@HAVE_FIRETUNNEL@
 HAVE_PRIVATE_HOME=@HAVE_PRIVATE_HOME@
 HAVE_GCOV=@HAVE_GCOV@
 HAVE_SELINUX=@HAVE_SELINUX@
-ifeq (@HAVE_SUID@, yes)
-HAVE_SUID=-DHAVE_SUID
-else
-HAVE_SUID=
-endif
+HAVE_SUID=@HAVE_SUID@
 HAVE_DBUSPROXY=@HAVE_DBUSPROXY@
 HAVE_USERTMPFS=@HAVE_USERTMPFS@
 HAVE_OUTPUT=@HAVE_OUTPUT@