Redirect stderr of lspci invocations to separate files

Otherwise executing lspci might spill something like:

  # lspci -vvnn > /dev/null
  pcilib: sysfs_read_vpd: read failed: No such device

Which according to https://bugzilla.kernel.org/show_bug.cgi?id=199467
isn't an "actual" error, but there is just no VPD EEPROM present.
But as long as it shows up on stderr, it behaves like an error, so
let's also tread it like an error. :)

Related to #12
Thanks: Darshaka Pathirana for the bug report

grml-hwinfo

@@ -261,8 +261,8 @@ cd "${OUTDIR}" || exit 1
 
   # disks / devices
   [ -f /proc/scsi/scsi ] && cat /proc/scsi/scsi > scsi
-  exectest lspci && lspci -nn > ./lspci
-  exectest lspci && lspci -vvnn > ./lspci_verbose
+  exectest lspci && lspci -nn >./lspci 2>./lspci.error
+  exectest lspci && lspci -vvnn >./lspci_verbose 2>./lspci_verbose.error
   cat /proc/partitions > partitions
   find /proc/ide/ -name geometry -exec grep . {} \; > proc_ide 2>/dev/null
   df -h > ./df 2>/dev/null