cmake: rename libssh2-config.cmake.in to libssh2-config.in.cmake

To:
- match filename suffix with file content.
- simplify recognizing CMake sources.
- ensure syntax highlighters use the correct file type.

Also:
- cmakelint.sh: simplify, alpha sort the filelist.

Closes #1765

ci/cmakelint.sh

@@ -14,7 +14,7 @@
 # cmake-lint can be installed from PyPi with the command "python3 -m pip
 # install cmakelang".
 #
-# The xargs invocation is portable, but does not preserve spaces in file names.
+# The xargs invocation is portable, but does not preserve spaces in filenames.
 # If such a file is ever added, then this can be portably fixed by switching to
 # "xargs -I{}" and appending {} to the end of the xargs arguments (which will
 # call cmakelint once per file) or by using the GNU extension "xargs -d'\n'".
@@ -25,15 +25,13 @@ cd "$(dirname "$0")"/..
 
 {
   if [ -n "${1:-}" ]; then
-    for A in "$@"; do printf "%s\n" "$A"; done
+    for A in "$@"; do printf '%s\n' "$A"; done
   elif git rev-parse --is-inside-work-tree >/dev/null 2>&1; then
-    git ls-files
+    git ls-files '**CMakeLists.txt' '*.cmake'
   else
-    # strip off the leading ./ to make the grep regexes work properly
-    find . -type f | sed 's@^\./@@'
+    find . -type f \( -name 'CMakeLists.txt' -o -name '*.cmake' \)
   fi
-} | grep -E '(^CMake|/CMake|\.cmake$|\.cmake\.in$)' | grep -v -E '(\.h\.cmake|\.c)$' \
-  | xargs \
+} | sort | xargs \
   cmake-lint \
     --suppress-decorations \
     --disable \

src/CMakeLists.txt

@@ -218,7 +218,7 @@ if(NOT LIBSSH2_DISABLE_INSTALL)
   export(PACKAGE ${PROJECT_NAME})  # register it
 
   # Generate libssh2-config.cmake into build tree and install it with dependencies
-  configure_file("${PROJECT_SOURCE_DIR}/cmake/libssh2-config.cmake.in" "${PROJECT_NAME}-config.cmake" @ONLY)
+  configure_file("${PROJECT_SOURCE_DIR}/cmake/libssh2-config.in.cmake" "${PROJECT_NAME}-config.cmake" @ONLY)
   install(
     FILES
       "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}-config.cmake"