dyndbg: fix old BUG_ON in >control parser

stable inclusion
from stable-v4.19.314
commit 3c718bddddca9cbef177ac475b94c5c91147fb38
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9QGMG
CVE: CVE-2024-35947

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=41d8ac238ab1cab01a8c71798d61903304f4e79b



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commit 00e7d3bea2ce7dac7bee1cf501fb071fd0ea8f6c upstream.

Fix a BUG_ON from 2009.  Even if it looks "unreachable" (I didn't
really look), lets make sure by removing it, doing pr_err and return
-EINVAL instead.

Cc: stable <stable@kernel.org>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Link: https://lore.kernel.org/r/20240429193145.66543-2-jim.cromie@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>