CSmith test script: avoid a need for argv modelling

With additional checks turned on as of #8093, we failed CSmith tests
with (legitimate) pointer property failures in `strcmp`. These are
caused by trying to compare `argv[1]` to a string. As we do not model
`argv` in these tests, `argv[1]` was not a valid pointer. This fix just
removes the string comparison, which is only used for turning on/off
debug output in test execution.

Author: tautschnig

scripts/csmith.sh

@@ -60,6 +60,9 @@ csmith_test() {
   # Prepare the test CBMC by injecting the checksum as an assertion.
   gcc -E -I/usr/include/csmith -D__FRAMAC \
     -D'Frama_C_dump_assert_each()'="assert($check==(crc))" $f -o $bn.i
+  # We don't model argv here, so make sure we don't end up with a spurious
+  # null-pointer use.
+  sed -i 's/strcmp(argv\[1\], "1")/0/' $bn.i
   # Run the test using CBMC for up to 90 seconds, unwinding loops up to 257
   # times.
   ec=0