Fix some minore trailing whitespace & lint errors

Author: zbeekman

src/tests/installation/installation-scripts.sh

@@ -129,11 +129,11 @@ function cleanup_before_exit() {
 }
 trap cleanup_before_exit EXIT # The signal is specified here. Could be SIGINT, SIGTERM etc.
 
-pushd "${OPENCOARRAYS_SRC_DIR}"/src/tests/installation
+pushd "${OPENCOARRAYS_SRC_DIR}"/src/tests/installation || exit 1
 
 # shellcheck source=../../../prerequisites/stack.sh
 source "${OPENCOARRAYS_SRC_DIR}"/prerequisites/stack.sh
 source test-stack.sh
 test_stack
 
-popd
+popd || exit 1

src/tests/installation/installation-scripts.sh-usage

@@ -1,11 +1,11 @@
   -b --install-branch [arg]   Install the specified repository development branch.
   -B --list-branches [arg]    List the available branches in the specified package's repository.
-  -c --with-c [arg]           Use specified C compiler. 
-  -C --with-cxx [arg]         Use specified C++ compiler. 
+  -c --with-c [arg]           Use specified C compiler.
+  -C --with-cxx [arg]         Use specified C++ compiler.
   -d --debug                  Enable debug mode.
   -D --print-downloader [arg] Print download program for package specified in argument.
   -e --verbose                Enable verbose mode, print script as it is executed.
-  -f --with-fortran [arg]     Use specified Fortran compiler. 
+  -f --with-fortran [arg]     Use specified Fortran compiler.
   -h --help                   Print this page.
   -i --install-prefix [arg]   Install package in specified path. Default="${OPENCOARRAYS_SRC_DIR}/prerequisites/installations/${package_name:-}/${version_to_build:-}"
   -I --install-version [arg]  Install package version.