intelEKcert2PemDer.sh: do not modify input cert
intelEKcert2PemDer.sh: do not modify input cert

Rather than using sed modifiy in place (-i), on the input
certificate, build a pipeline to process the stream, leaving
the original intact.

Fixes: #186

Signed-off-by: William Roberts <60148e894dabf0b83bde1d460768794cd453c455@intel.com>

01org/tpm2.0-tools,martinezjavier/tpm2-tools,martinezjavier/tpm2-tools,martinezjavier/tpm2-tools,01org/tpm2.0-tools,01org/tpm2.0-tools,martinezjavier/tpm2-tools