testinfra/modules/blockdevice: Don't fail on stderr (#745)

The `blockdevice` module raises a `RuntimeError` if `blockdev` returns with a
non-zero exit code, or if stderr is not empty.

But the latter can happen even when there's no failure at all, for instance if
`sshd` has a banner message configured (which gets output to stderr whenever
someone connects to the host).

Signed-off-by: Benoît Knecht <bknecht@protonmail.ch>

Author: BenoitKnecht

testinfra/modules/blockdevice.py

@@ -130,7 +130,7 @@ def _data(self):
         header = ["RO", "RA", "SSZ", "BSZ", "StartSec", "Size", "Device"]
         command = "blockdev  --report %s"
         blockdev = self.run(command, self.device)
-        if blockdev.rc != 0 or blockdev.stderr:
+        if blockdev.rc != 0:
             raise RuntimeError("Failed to gather data: {}".format(blockdev.stderr))
         output = blockdev.stdout.splitlines()
         if len(output) < 2: