cmake: make formatting of install statements follow one pattern

Change-Id: Ib7d571af629b0af78397a411b0cca409a6d218d8
diff --git a/docs/CMakeLists.txt b/docs/CMakeLists.txt
index ed0fe3d..d2f9b1c 100644
--- a/docs/CMakeLists.txt
+++ b/docs/CMakeLists.txt
@@ -54,7 +54,11 @@
     message(WARNING "rst2man from python-docutils is required to build man pages")
 else()
     build_man_page(MAN1_OUTPUT grgsm_livemon.rst grgsm_livemon.1)
-    install(FILES ${MAN1_OUTPUT} DESTINATION ${CMAKE_INSTALL_PREFIX}/share/man/man1)
+    install(
+        FILES
+        ${MAN1_OUTPUT}
+        DESTINATION ${CMAKE_INSTALL_PREFIX}/share/man/man1
+    )
 endif()