make check fails on s390x

With b87e5bb7 $ make check fails on s390x

DEBUG: PASS: iv_viewerwidget
DEBUG: PASS: iv_fileops
DEBUG: FAIL: iv_bm_search
DEBUG: PASS: iv_datapresentation
DEBUG: PASS: iv_imagerenderer
DEBUG: PASS: iv_inputmodes
DEBUG: PASS: iv_textrenderer
DEBUG: PASS: utils_no_dependencies
DEBUG: ============================================================================
DEBUG: Testsuite summary for gnome-commander 1.13.0
DEBUG: ============================================================================
DEBUG: # TOTAL: 8
DEBUG: # PASS:  7
DEBUG: # SKIP:  0
DEBUG: # XFAIL: 0
DEBUG: # FAIL:  1
DEBUG: # XPASS: 0
DEBUG: # ERROR: 0
DEBUG: ============================================================================
DEBUG: See tests/test-suite.log
DEBUG: Please report to https://gitlab.gnome.org/GNOME/gnome-commander/issues
DEBUG: ============================================================================

iv_bm_search.log says:

[==========] Running 2 tests from 1 test suite.
[----------] Global test environment set-up.
[----------] 2 tests from BmByteTest
[ RUN      ] BmByteTest.match_test
Good suffices table:
5 5 5 5 5 7 1 

Bad characters table:
Char(ASCII)	Value
(1)		1
(4)		5
�(180)		4
�(254)		3
(All other characters have value of 7)

 Found match at offset = 142
 Found match at offset = 248
[       OK ] BmByteTest.match_test (1 ms)
[ RUN      ] BmByteTest.chartype_test
/builddir/build/BUILD/gnome-commander-git/gnome-commander/_builddir/../tests/iv_bm_search_test.cc:186: Failure
Expected equality of these values:
  found_at
    Which is: 0
  217
String with UTF-8 letters not found in text where it should be found.
[  FAILED  ] BmByteTest.chartype_test (4 ms)
[----------] 2 tests from BmByteTest (6 ms total)

[----------] Global test environment tear-down
[==========] 2 tests from 1 test suite ran. (9 ms total)
[  PASSED  ] 1 test.
[  FAILED  ] 1 test, listed below:
[  FAILED  ] BmByteTest.chartype_test

 1 FAILED TEST
FAIL iv_bm_search (exit status: 1)