udev: do not use a separate lock for udev block scripts

Since migration to QubesDB, it isn't needed anymore (QubesDB have no
problem with concurrent writes, as transactions are not supported).
This should speedup system startup.

udev/udev-qubes-block.rules

@@ -16,8 +16,8 @@ ENV{MAJOR}=="253", ENV{DM_NAME}=="origin-*", GOTO="qubes_block_end"
 ENV{MAJOR}=="253", ENV{DM_NAME}=="", GOTO="qubes_block_end"
 
 IMPORT{db}="QUBES_EXPOSED"
-ACTION=="add", IMPORT{program}="/usr/bin/flock /var/run/qubes-udev.lock -c /usr/libexec/qubes/udev-block-add-change"
-ACTION=="change", IMPORT{program}="/usr/bin/flock /var/run/qubes-udev.lock -c /usr/libexec/qubes/udev-block-add-change"
+ACTION=="add", IMPORT{program}="/usr/libexec/qubes/udev-block-add-change"
+ACTION=="change", IMPORT{program}="/usr/libexec/qubes/udev-block-add-change"
 ACTION=="remove", RUN+="/usr/libexec/qubes/udev-block-remove"
 
 LABEL="qubes_block_end"