cmake.bbclass: Do not use bitbake variable syntax for shell variables

Using bitbake variable syntax (i.e., ${FOO}) for shell variables is
bad practice. First of all it is confusing, but more importantly it
can lead to weird problems if someone actually defines a bitbake
variable with the same name as the shell variable.

Also use lower case for local shell variables.

(From OE-Core rev: ea6befae799f45cf93771442f242cb023dd809d1)

Signed-off-by: Peter Kjellerstedt <peter.kjellerstedt@axis.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/cmake.bbclass

@@ -43,12 +43,12 @@ def map_target_arch_to_uname_arch(target_arch):
 
 cmake_do_generate_toolchain_file() {
 	if [ "${BUILD_SYS}" = "${HOST_SYS}" ]; then
-	    CMAKE_CROSSCOMPILING="set( CMAKE_CROSSCOMPILING FALSE )"
+		cmake_crosscompiling="set( CMAKE_CROSSCOMPILING FALSE )"
 	fi
 	cat > ${WORKDIR}/toolchain.cmake <<EOF
 # CMake system name must be something like "Linux".
 # This is important for cross-compiling.
-${CMAKE_CROSSCOMPILING}
+$cmake_crosscompiling
 set( CMAKE_SYSTEM_NAME `echo ${TARGET_OS} | sed -e 's/^./\u&/' -e 's/^\(Linux\).*/\1/'` )
 set( CMAKE_SYSTEM_PROCESSOR ${@map_target_arch_to_uname_arch(d.getVar('TARGET_ARCH'))} )
 set( CMAKE_C_COMPILER ${OECMAKE_C_COMPILER} )
@@ -107,13 +107,13 @@ cmake_do_configure() {
 
 	# Just like autotools cmake can use a site file to cache result that need generated binaries to run
 	if [ -e ${WORKDIR}/site-file.cmake ] ; then
-		OECMAKE_SITEFILE=" -C ${WORKDIR}/site-file.cmake"
+		oecmake_sitefile="-C ${WORKDIR}/site-file.cmake"
 	else
-		OECMAKE_SITEFILE=""
+		oecmake_sitefile=
 	fi
 
 	cmake \
-	  ${OECMAKE_SITEFILE} \
+	  $oecmake_sitefile \
 	  ${OECMAKE_SOURCEPATH} \
 	  -DCMAKE_INSTALL_PREFIX:PATH=${prefix} \
 	  -DCMAKE_INSTALL_BINDIR:PATH=${@os.path.relpath(d.getVar('bindir'), d.getVar('prefix'))} \