Clarify Infiniband collector support (prometheus#643)

Tested a DL360 Gen9 box with an Omni-Path adapter in it. The existing InfiniBand collector can provide support for the same metrics on Omni-Path cards as well.

Signed-Off-By: Joe Handzik <[email protected]>

README.md

@@ -32,7 +32,7 @@ exec | Exposes execution statistics. | Dragonfly, FreeBSD
 filefd | Exposes file descriptor statistics from `/proc/sys/fs/file-nr`. | Linux
 filesystem | Exposes filesystem statistics, such as disk space used. | Darwin, Dragonfly, FreeBSD, Linux, OpenBSD
 hwmon | Expose hardware monitoring and sensor data from `/sys/class/hwmon/`. | Linux
-infiniband | Exposes network statistics specific to InfiniBand configurations. | Linux
+infiniband | Exposes network statistics specific to InfiniBand and Intel OmniPath configurations. | Linux
 ipvs | Exposes IPVS status from `/proc/net/ip_vs` and stats from `/proc/net/ip_vs_stats`. | Linux
 loadavg | Exposes load average. | Darwin, Dragonfly, FreeBSD, Linux, NetBSD, OpenBSD, Solaris
 mdadm | Exposes statistics about devices in `/proc/mdstat` (does nothing if no `/proc/mdstat` present). | Linux