Simplify find_first_of & find_last_of on single char.

Summary:
When calling find_first_of and find_last_of on a single character,
we can instead just call find / rfind and make our intent more
clear.

Reviewers: clayborg

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D12518

llvm-svn: 246609
diff --git a/lldb/tools/lldb-mi/MICmdArgValFile.cpp b/lldb/tools/lldb-mi/MICmdArgValFile.cpp
index 9e59dec..7f5b20e 100644
--- a/lldb/tools/lldb-mi/MICmdArgValFile.cpp
+++ b/lldb/tools/lldb-mi/MICmdArgValFile.cpp
@@ -142,8 +142,8 @@
     if (vrFileNamePath.empty())
         return false;
 
-    const bool bHavePosSlash = (vrFileNamePath.find_first_of("/") != std::string::npos);
-    const bool bHaveBckSlash = (vrFileNamePath.find_first_of("\\") != std::string::npos);
+    const bool bHavePosSlash = (vrFileNamePath.find('/') != std::string::npos);
+    const bool bHaveBckSlash = (vrFileNamePath.find('\\') != std::string::npos);
 
     // Look for --someLongOption
     size_t nPos = vrFileNamePath.find("--");
@@ -152,13 +152,13 @@
         return false;
 
     // Look for -f type short parameters
-    nPos = vrFileNamePath.find_first_of("-");
+    nPos = vrFileNamePath.find('-');
     const bool bShort = (nPos == 0);
     if (bShort)
         return false;
 
     // Look for i1 i2 i3....
-    nPos = vrFileNamePath.find_first_of("i");
+    nPos = vrFileNamePath.find('i');
     const bool bFoundI1 = ((nPos == 0) && (::isdigit(vrFileNamePath[1])));
     if (bFoundI1)
         return false;