compile-options: Fixed shellcheck warnings

Signed-off-by: Lars Erik Wik <lars.erik.wik@northern.tech>

Author: larsewi

build-scripts/compile-options

@@ -5,7 +5,7 @@
 
 # Autodect PROJECT if not set
 
-if [ x"$PROJECT" = x ]
+if [ -z "$PROJECT" ]
 then
     case x"$JOB_NAME" in
         *-community-*)   PROJECT=community;;
@@ -18,9 +18,9 @@ fi
 # If still not set, then either we are running outside Jenkins, or this
 # is not a main "build" type job (it could be the bootstrap job).
 # Do directory-based auto-detection.
-if [ x"$PROJECT" = x ]
+if [ -z "$PROJECT" ]
 then
-   if [ -d $BASEDIR/nova ]
+   if [ -d "$BASEDIR"/nova ]
    then
        PROJECT=nova
    else
@@ -34,7 +34,7 @@ export PROJECT
 # When running manually, you can just export this variable.
 # It's a flag: if it's set to 1 - then we use system OpenSSL.
 # Otherwise, we build it.
-if [ x"$SYSTEM_SSL" = x ]
+if [ -z "$SYSTEM_SSL" ]
 then
     # We don't bundle OpenSSL on RHEL 8 (and newer in the future)
     if [ "$OS" = "rhel" ] && expr "$OS_VERSION" ">=" "8" >/dev/null
@@ -82,7 +82,7 @@ case "$OS_FAMILY" in
 esac
 
 # When we don't bundle OpenSSL, then we need to pull it from /usr/lib64.
-if [ x"$SYSTEM_SSL" = x1 ]
+if [ "$SYSTEM_SSL" = 1 ]
 then
   LDFLAGS="$LDFLAGS -L/usr/lib64"
 fi
@@ -100,7 +100,7 @@ EMBEDDED_DB="lmdb"
 ############### Fill in build dependencies in DEPS variable ################
 
 DEPS=
-[ $OS_FAMILY = mingw ]  &&  var_append DEPS "pthreads-w32 libgnurx"
+[ "$OS_FAMILY" = mingw ]  &&  var_append DEPS "pthreads-w32 libgnurx"
 
 # libgcc_s.so is needed before we compile any other dependency
 #             on some platforms!
@@ -110,7 +110,7 @@ esac
 
 var_append DEPS "$EMBEDDED_DB pcre2"
 
-if ! [ x"$SYSTEM_SSL" = x1 ]
+if ! [ "$SYSTEM_SSL" = 1 ]
 then
   # FIXME: Why do we need zlib?
   # ANSWER: Openssl uses it optionally, TODO DISABLE
@@ -160,7 +160,7 @@ case "$EXPLICIT_ROLE" in
     hub)   ROLE=hub;;
     *)
         # Not running under Jenkins?
-        if [ x"$JENKINS_SERVER_COOKIE" = x ]
+        if [ -z "$JENKINS_SERVER_COOKIE" ]
         then
             case "$PROJECT-$ARCH-$OS-${OS_VERSION}" in
                 community-*) ROLE=agent;;