irmp: silence printf(3) format warnings (simple approach)

irmp: silence printf(3) format warnings (simple approach)

Pick low hanging fruit. Stick with the previous implementation's format
specifiers, assume that they work on all platforms which IRMP supports.
Cast arguments to mere integers where necessary instead, again assume
that their range fits as they did in the previous implementation. This
silences several of these compiler warnings:

  irmp.c:3332:25: warning: format ‘%d’ expects argument of type ‘int’, but argument 4 has type ‘long unsigned int’ [-Wformat=]
                           ANALYZE_PRINTF ("protocol = NIKON, start bit timings: pulse: %3d - %3d, pause: %3d - %3d\n",
                           ^