fscrypt 0.3.3-1 FTBFS on ppc64el

On ppc64el, many of the tests fail with "could not lock key in memory":

=== RUN TestMakeKeys
    crypto_test.go:107: could not lock key in memory
--- FAIL: TestMakeKeys (0.00s)
=== RUN TestWipe
    crypto_test.go:128: could not lock key in memory
--- FAIL: TestWipe (0.00s)
=== RUN TestInvalidLength
--- PASS: TestInvalidLength (0.00s)
=== RUN TestZeroLength
    crypto_test.go:157: could not lock key in memory
--- FAIL: TestZeroLength (0.00s)
=== RUN TestEnableDisableMemoryLocking
    crypto_test.go:176: could not lock key in memory
--- FAIL: TestEnableDisableMemoryLocking (0.00s)
=== RUN TestDisableEnableMemoryLocking
--- PASS: TestDisableEnableMemoryLocking (0.00s)
=== RUN TestKeyResize
    crypto_test.go:205: could not lock key in memory
--- FAIL: TestKeyResize (0.00s)
=== RUN TestKeyLargeResize
--- PASS: TestKeyLargeResize (0.01s)
=== RUN TestRandomKeyGen
    crypto_test.go:245: could not lock key in memory
--- FAIL: TestRandomKeyGen (0.00s)
=== RUN TestBigKeyGen
--- PASS: TestBigKeyGen (0.00s)
=== RUN TestKeysAndOutputsDistinct
--- FAIL: TestKeysAndOutputsDistinct (0.00s)

This is reminiscent of bug 2004435, where kitty's test-suite would fail because RLIMIT_MEMLOCK is too low on ppc64el builders.