hplip: udev rule: drop nohup instead of patching it

hplip's udev rule uses `nohup` to attempt to detach
its printer configuration script from the udev process.
However, this attempt is futile as udev
tracks its child processes with cgroups:
https://unix.stackexchange.com/a/243648

The hardcoded path to `nohup` was patched to use Nix' `nohup`.
This commit alters the patch script so
that it simply drops the call to `nohup`.

pkgs/misc/drivers/hplip/3.16.11.nix

@@ -176,7 +176,7 @@ pythonPackages.buildPythonApplication {
     # Needs a lot of patching but might save someone a bit of confusion:
     substituteInPlace $out/etc/udev/rules.d/56-hpmud.rules \
       --replace {,${bash}}/bin/sh \
-      --replace {/usr,${coreutils}}/bin/nohup \
+      --replace /usr/bin/nohup "" \
       --replace {,${utillinux}/bin/}logger \
       --replace {/usr,$out}/bin
   '';

pkgs/misc/drivers/hplip/3.18.5.nix

@@ -208,7 +208,7 @@ pythonPackages.buildPythonApplication {
     # Needs a lot of patching but might save someone a bit of confusion:
     substituteInPlace $out/etc/udev/rules.d/56-hpmud.rules \
       --replace {,${bash}}/bin/sh \
-      --replace {/usr,${coreutils}}/bin/nohup \
+      --replace /usr/bin/nohup "" \
       --replace {,${utillinux}/bin/}logger \
       --replace {/usr,$out}/bin
   '';

pkgs/misc/drivers/hplip/default.nix

@@ -215,7 +215,7 @@ pythonPackages.buildPythonApplication {
     # Needs a lot of patching but might save someone a bit of confusion:
     substituteInPlace $out/etc/udev/rules.d/56-hpmud.rules \
       --replace {,${bash}}/bin/sh \
-      --replace {/usr,${coreutils}}/bin/nohup \
+      --replace /usr/bin/nohup "" \
       --replace {,${utillinux}/bin/}logger \
       --replace {/usr,$out}/bin
   '';