Done with "sed -i 's/^#include //' `git grep -l ^#include modules`".

* modules/alloca: Use only header name; no need to list #include.
* modules/alloca-opt: Likewise.
* modules/arpa_inet: Likewise.
* modules/canon-host: Likewise.
* modules/configmake: Likewise.
* modules/dirent: Likewise.
* modules/eealloc: Likewise.
* modules/environ: Likewise.
* modules/fchdir: Likewise.
* modules/fcntl: Likewise.
* modules/fcntl-h: Likewise.
* modules/gethrxtime: Likewise.
* modules/gettime: Likewise.
* modules/ignore-value: Likewise.
* modules/inet_ntop: Likewise.
* modules/inet_pton: Likewise.
* modules/inttypes: Likewise.
* modules/isnand-nolibm: Likewise.
* modules/isnanf-nolibm: Likewise.
* modules/mbchar: Likewise.
* modules/mbfile: Likewise.
* modules/mbiter: Likewise.
* modules/mbuiter: Likewise.
* modules/netdb: Likewise.
* modules/netinet_in: Likewise.
* modules/nproc: Likewise.
* modules/pagealign_alloc: Likewise.
* modules/poll: Likewise.
* modules/printf-frexp: Likewise.
* modules/pthread: Likewise.
* modules/putenv: Likewise.
* modules/random_r: Likewise.
* modules/relocatable-prog: Likewise.
* modules/search: Likewise.
* modules/select: Likewise.
* modules/selinux-h: Likewise.
* modules/settime: Likewise.
* modules/signal: Likewise.
* modules/size_max: Likewise.
* modules/socklen: Likewise.
* modules/ssize_t: Likewise.
* modules/stdarg: Likewise.
* modules/stdbool: Likewise.
* modules/stddef: Likewise.
* modules/stdint: Likewise.
* modules/stdio: Likewise.
* modules/stdlib: Likewise.
* modules/string: Likewise.
* modules/strings: Likewise.
* modules/sys_file: Likewise.
* modules/sys_ioctl: Likewise.
* modules/sys_select: Likewise.
* modules/sys_socket: Likewise.
* modules/sys_stat: Likewise.
* modules/sys_time: Likewise.
* modules/sys_times: Likewise.
* modules/sys_utsname: Likewise.
* modules/sys_wait: Likewise.
* modules/sysexits: Likewise.
* modules/time: Likewise.
* modules/times: Likewise.
* modules/tmpfile: Likewise.
* modules/trim: Likewise.
* modules/unistd: Likewise.
* modules/wchar: Likewise.
* modules/wctype: Likewise.

Signed-off-by: Eric Blake <ebb9@byu.net>