This commit changes behavior of `eu-elfcompress` from what before was success to error - when 'Nothing to do' conditions are meet.

```
commit ed62996defc619d0def86a5ed223a48486b97a70
Author: Mark Wielaard <mark@klomp.org>
Date:   Sat Jul 21 17:07:12 2018 +0200

    elfcompress: Don't rewrite file if no section data needs to be updated.
    
    If the input and output file are the same and no section needs to
    be updated we really don't need to rewrite the file.
    
    Check whether any matching section is already compressed or decompressed.
    Skip the section if it doesn't need to be changed. If no section data
    needs updating end with success without rewriting/updating file.
    
    With --force the file will still always be updated/rewritten even if
    no section data needs to be (de)compressed.
    
    Acked-by: Igor Gnatenko <ignatenkobrain@fedoraproject.org>
    Signed-off-by: Mark Wielaard <mark@klomp.org>
---
 src/ChangeLog     |  7 +++++++
 src/elfcompress.c | 45 ++++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 49 insertions(+), 3 deletions(-)

```

Is this change of behavior intentional? (Now it breaks debuginfo processing of kernel modules in ALT Linux).

  + eu-elfcompress --verbose ./usr/lib/debug/lib/modules/5.10.35-std-def-alt1/fs/unicode/zunicode.ko.debug
  processing: ./usr/lib/debug/lib/modules/5.10.35-std-def-alt1/fs/zcommon/zcommon.ko.debug
  Nothing to do.
  Command exited with non-zero status 1

Also, exit(-1) is incorrect exit code in general.