man/docker-build.1: typo in parameter variable: CID => IID

--iidfile logically specifies the IIDFILE and not the CIDFILE
(use --cidfile from docker-run.1.md for specifying a cidfile).

Signed-off-by: Max-Julian Pogner <max-julian@pogner.at>

man/docker-build.1.md

@@ -11,7 +11,7 @@ docker-build - Build an image from a Dockerfile
 [**-c**|**--cpu-shares**[=*0*]]
 [**--cgroup-parent**[=*CGROUP-PARENT*]]
 [**--help**]
-[**--iidfile**[=*CIDFILE*]]
+[**--iidfile**[=*IIDFILE*]]
 [**-f**|**--file**[=*PATH/Dockerfile*]]
 [**-squash**] *Experimental*
 [**--force-rm**]