fixed patch file name and patch prefix strip in spec file

OBS-URL: https://build.opensuse.org/package/show/network:dhcp/dhcp?expand=0&rev=41

dhcp.spec

@@ -85,7 +85,7 @@ Patch30:        dhcp-4.1.1-dhclient-no-libcrypto.diff
 %endif
 Patch40:        dhcp-4.1.1-P1-lpf-bind-msg-fix.diff
 Patch41:        dhcp-4.1.1-P1-relay-no-ip-on-interface.diff
-Patch42:        dhcp-4.1.1-P1-slp-loop.diff
+Patch42:        dhcp-4.1.1-P1-optional-value-infinite-loop.diff
 ##
 PreReq:         /bin/touch /sbin/chkconfig sysconfig
 BuildRoot:      %{_tmppath}/%{name}-%{version}-build
@@ -211,8 +211,8 @@ Authors:
 %patch30 -p1
 %endif
 %patch40 -p1
-%patch41 -p0
-%patch42 -p0
+%patch41 -p1
+%patch42 -p1
 ##
 find . -type f -name \*.cat\* -exec rm -f {} \;
 dos2unix contrib/ms2isc/*