Move icE1usb specific chapters to chapters/icE1usb/ to prepare for
the upcoming e1-tracer user manual.
Change-Id: I4c6cdd4036051469640b86860ea19736aa04364a
Prevent the following error (generating manuals seemed to work fine
regardless):
realpath: missing operand
Try 'realpath --help' for more information.
make: Nothing to be done for 'all'.
Change-Id: I72a62b86cba0dfd710f7e1c4c01a3c10710128d8
Instead of only relying on pkg-config, support the environment variable
and fallback path like in other Osmocom repositories too. The same
script is used in other Osmocom repositories where manuals are built
without autotools.
Related: OS#4912
Change-Id: Iecfbfc2a7588c316642aa37be637cf3c02f76ac4