MAINTAINERS: update BPF JIT S390 maintainers

Ilya Leoshkevich is joining as s390 bpf maintainer. With his background
as gcc developer he would be valuable for the team and community as a
whole. Ilya, have fun!

Since there is now enough eyes on s390 bpf, relieve Christian Borntraeger,
so that he could focus on his maintainer tasks for other components.
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>
Acked-by: NChristian Borntraeger <borntraeger@e.ibm.com>
Acked-by: NIlya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

MAINTAINERS

@@ -3082,9 +3082,9 @@ S:	Maintained
 F:	arch/riscv/net/
 
 BPF JIT for S390
+M:	Ilya Leoshkevich <iii@linux.ibm.com>
 M:	Heiko Carstens <heiko.carstens@de.ibm.com>
 M:	Vasily Gorbik <gor@linux.ibm.com>
-M:	Christian Borntraeger <borntraeger@de.ibm.com>
 L:	netdev@vger.kernel.org
 L:	bpf@vger.kernel.org
 S:	Maintained