Build: Use sh instead of ls for ELF configuration

On RHEL variants, if coreutils-single is installed, ls is a script
that contains:

#!/usr/bin/coreutils --coreutils-prog-shebang=ls

Replace ls with sh, which is supposed to be a binary (or a symlink
to one) everywhere.

Pick-to: 6.7 6.6
Change-Id: I2a43ac9e3332a470951bbf3335f2fdf3ae5c698c
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/CMakeLists.txt

@@ -418,7 +418,7 @@ set_source_files_properties(
 # Find ELF interpreter and define a macro for that:
 if ((LINUX OR HURD) AND NOT CMAKE_CROSSCOMPILING AND BUILD_SHARED_LIBS)
     if (NOT DEFINED ELF_INTERPRETER)
-        execute_process(COMMAND ${CMAKE_COMMAND} -E env LC_ALL=C readelf -l /bin/ls
+        execute_process(COMMAND ${CMAKE_COMMAND} -E env LC_ALL=C readelf -l /bin/sh
                         RESULT_VARIABLE readelf_ok
                         OUTPUT_VARIABLE readelf_output
                        )