Rename linux_ubsan_clang_vptr to linux_ubsan_vptr.

I mistyped the name of the bot as 'linux_ubsan_clang_vptr'.
The real name is 'linux_ubsan_vptr'.

Also erase the libfuzzer bot, since it's alreading using GN.

BUG=589510
NOTRY=True

Review-Url: https://codereview.webrtc.org/2227043002
Cr-Commit-Position: refs/heads/master@{#13695}
diff --git a/webrtc/build/mb_config.pyl b/webrtc/build/mb_config.pyl
index 370031c..20522aa 100644
--- a/webrtc/build/mb_config.pyl
+++ b/webrtc/build/mb_config.pyl
@@ -44,8 +44,6 @@
       'Linux64 Release [large tests]': 'gyp_release_bot_x64',
       'Linux64 Debug (GN)': 'gn_openh264_debug_bot_x64',
       'Linux64 Release (GN)': 'gn_openh264_release_bot_x64',
-      'Linux64 Release (Libfuzzer)':
-        'gn_openh264_libfuzzer_asan_clang_release_bot_x64',
     },
     'tryserver.webrtc': {
       # iOS
@@ -71,7 +69,7 @@
       'linux_msan': 'gyp_msan_clang_release_trybot_x64',
       'linux_tsan2': 'gyp_tsan_clang_release_trybot_x64',
       'linux_ubsan': 'gyp_ubsan_clang_release_trybot_x64',
-      'linux_ubsan_clang_vptr': 'gyp_ubsan_vptr_clang_release_trybot_x64',
+      'linux_ubsan_vptr': 'gyp_ubsan_vptr_clang_release_trybot_x64',
       'linux_baremetal': 'gyp_release_trybot_x64',
       'linux_swarming': 'swarming_gyp_debug_trybot_x64',
     },
@@ -174,9 +172,6 @@
     'gn_openh264_release_bot_x64': [
       'gn', 'openh264', 'release_bot', 'x64'
     ],
-    'gn_openh264_libfuzzer_asan_clang_release_bot_x64': [
-      'gn', 'openh264', 'libfuzzer', 'asan', 'clang', 'release_bot', 'x64'
-    ],
     # Linux trybot
     'gyp_release_trybot_arm': [
       'gyp', 'release_trybot', 'arm'
@@ -293,8 +288,6 @@
       'mixins': ['ios_release_bot', 'dcheck_always_on']
     },
 
-    'libfuzzer': { 'gn_args': 'use_libfuzzer=true' },
-
     'lsan': {
       'gn_args': 'is_lsan=true',
       'gyp_defines': 'lsan=1',