cmph: Remove C99ism and other fixes

cmph: Remove C99ism and other fixes

...So that it will compile on non-C99 compilers.  The changes are mainly
moving the variable declarations to the start of the resecptive blocks.

Also, replace the use of buflen in chd.c as it might not be defined for all
platforms, instead using packed_cr_size as it seems to represent the value
that is to be printed/displayed by the debugging output.

https://bugzilla.gnome.org/show_bug.cgi?id=681820