classes/terminal: fix pseudo exiting when launching devshell

In dylan, since the entire bitbake process is run under pseudo,
LD_PRELOAD is set when we collect BB_ORIGENV and thus when we construct
the devshell environment from the latter, LD_PRELOAD is included.
However, for a fakeroot task we explicitly run the devshell under pseudo
(e.g. "pseudo /bin/bash"), and if LD_PRELOAD is set to preload
libpseudo.so when pseudo is run, it seems to exit immediately without
error. Since LD_PRELOAD shouldn't be exported anyway, exclude this from
the environment so it doesn't prevent running the shell.

(From OE-Core rev: 88866d93b1a99a921d390044a8399c3ef24dc977)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/terminal.bbclass

@@ -62,6 +62,10 @@ def oe_terminal(command, title, d):
             envdata.setVar(key, str(value))
             envdata.setVarFlag(key, 'export', 1)
 
+    # LD_PRELOAD of pseudo will cause problems if this is a fakeroot task
+    # and we shouldn't be exporting it anyway
+    envdata.delVar('LD_PRELOAD')
+
     # Replace command with an executable wrapper script
     command = emit_terminal_func(command, envdata, d)