s390/decompressor: discard __ex_table section

Exception table (__ex_table section) is not used during the decompressor
phase and could be discarded to save the memory. It is currently
generated due to sclp_service_call function (sclp_early_core.c). An
assumption is that decompressor usage of sclp_service_call via
sclp_early_printk should never trigger exceptions.
Signed-off-by: NVasily Gorbik <gor@linux.vnet.ibm.com>
Acked-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/boot/compressed/vmlinux.lds.S

@@ -52,6 +52,7 @@ SECTIONS
 	/* Sections to be discarded */
 	/DISCARD/ : {
 		*(.eh_frame)
+		*(__ex_table)
 		*(*__ksymtab*)
 	}
 }