don't get confused by "[drm] init ..." type lines, when parsing

dmesg output for the kernel boot pieces. With thanks to Pat Lashley
for the sample

pybootchartgui/parsing.py

@@ -258,7 +258,7 @@ def is_relevant_line(linetokens):
 # [    0.039993] calling  migration_init+0x0/0x6b @ 1
 # [    0.039993] initcall migration_init+0x0/0x6b returned 1 after 0 usecs
 def _parse_dmesg(writer, file):
-	timestamp_re = re.compile ("^\[\S*([^\]]*)\S*]\s+(.*)$")
+ 	timestamp_re = re.compile ("^\[\s*(\d+\.\d+)\s*]\s+(.*)$")
 	split_re = re.compile ("^(\S+)\s+([\S\+_-]+) (.*)$")
 	processMap = {}
 	idx = 0