objtool: Reduce CONFIG_OBJTOOL_WERROR verbosity

Remove the following from CONFIG_OBJTOOL_WERROR:

  * backtrace

  * "upgraded warnings to errors" message

  * cmdline args

This makes the default output less cluttered and makes it easier to spot
the actual warnings.  Note the above options are still are available
with --verbose or OBJTOOL_VERBOSE=1.

Also, do the cmdline arg printing on all warnings, regardless of werror.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/d61df69f64b396fa6b2a1335588aad7a34ea9e71.1742852846.git.jpoimboe@kernel.org