x86/kexec: use pr_err() instead of kexec_dprintk() when an error occurs

x86/kexec: use pr_err() instead of kexec_dprintk() when an error occurs

When detecting an error, the current code uses kexec_dprintk() to output
log message. This is not quite appropriate as kexec_dprintk() is mainly
used for outputting debugging messages, rather than error messages.

Replace kexec_dprintk() with pr_err(). This also makes the output method
for this error log align with the output method for other error logs in
this function.

Additionally, the last return statement in set_page_address() is
unnecessary, remove it.

Link: https://lkml.kernel.org/r/20231220030124.149160-1-ytcoode@gmail.com
Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>