replace error_setg(&error_fatal, ...) with error_report()

replace error_setg(&error_fatal, ...) with error_report()

According to include/qapi/error.h:
* Please don't error_setg(&error_fatal, ...), use error_report() and
* exit(), because that's more obvious.

Patch updates all instances of error_setg(&error_fatal, ...) with
error_report(...), adds the explicit exit(1) and removes redundant
return statements.

Signed-off-by: Tudor Gheorghiu <tudor.reda@gmail.com>
Suggested-by: Thomas Huth <thuth@redhat.com>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2587
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
(Mjt: also fold __func__ to previous line)