tdefile elf plugin: prevent SEGV when unable to open an ELF file. This resolves issue TDE/tdebase#262.

Signed-off-by: Michele Calgaro <michele.calgaro@yahoo.it>
(cherry picked from commit a291f3a0a3)

tdefile-plugins/elf/tdefile_elf.cpp

@@ -97,6 +97,7 @@ bool KElfPlugin::readInfo( KFileMetaInfo& info, uint what)
 	if((handle = libr_open(const_cast<char*>(info.path().ascii()), access)) == NULL)
 	{
 		kdWarning() << "failed to open file" << info.path() << endl;
+		return false;
 	}
 
 	KFileMetaInfoGroup group = appendGroup(info, "Technical");