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.
Signed-off-by: Peter Kjellerstedt <peter.kjellerstedt@axis.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
